diff --git a/api/censuses.go b/api/censuses.go
index ab316127..fef09d2c 100644
--- a/api/censuses.go
+++ b/api/censuses.go
@@ -178,7 +178,7 @@ func (capi *census3API) createAndPublishCensus(req *CreateCensusRequest, qID str
 		// parse token information
 		tokensInfo := map[string]*strategyoperators.TokenInformation{}
 		for _, token := range strategyTokens {
-			tokensInfo[token.Symbol.String] = &strategyoperators.TokenInformation{
+			tokensInfo[token.Symbol] = &strategyoperators.TokenInformation{
 				ID:         common.BytesToAddress(token.ID).String(),
 				ChainID:    token.ChainID,
 				MinBalance: new(big.Int).SetBytes(token.MinBalance).String(),
diff --git a/api/strategies.go b/api/strategies.go
index b3885b11..3a640755 100644
--- a/api/strategies.go
+++ b/api/strategies.go
@@ -84,10 +84,10 @@ func (capi *census3API) getStrategies(msg *api.APIdata, ctx *httprouter.HTTPCont
 			return ErrCantGetStrategies.WithErr(err)
 		}
 		for _, strategyToken := range strategyTokens {
-			if !strategyToken.Symbol.Valid {
+			if strategyToken.Symbol == "" {
 				return ErrCantGetStrategies.With("invalid token symbol")
 			}
-			strategyResponse.Tokens[strategyToken.Symbol.String] = &StrategyToken{
+			strategyResponse.Tokens[strategyToken.Symbol] = &StrategyToken{
 				ID:         common.BytesToAddress(strategyToken.TokenID).String(),
 				ChainID:    strategyToken.ChainID,
 				MinBalance: new(big.Int).SetBytes(strategyToken.MinBalance).String(),
@@ -223,7 +223,7 @@ func (capi *census3API) getStrategy(msg *api.APIdata, ctx *httprouter.HTTPContex
 	}
 	// parse and encode tokens information
 	for _, tokenData := range tokensData {
-		strategy.Tokens[tokenData.Symbol.String] = &StrategyToken{
+		strategy.Tokens[tokenData.Symbol] = &StrategyToken{
 			ID:         common.BytesToAddress(tokenData.ID).String(),
 			MinBalance: new(big.Int).SetBytes(tokenData.MinBalance).String(),
 			ChainID:    tokenData.ChainID,
@@ -273,10 +273,10 @@ func (capi *census3API) getTokenStrategies(msg *api.APIdata, ctx *httprouter.HTT
 			return ErrCantGetStrategies.WithErr(err)
 		}
 		for _, strategyToken := range strategyTokens {
-			if !strategyToken.Symbol.Valid {
+			if strategyToken.Symbol == "" {
 				return ErrCantGetStrategies.With("invalid token symbol")
 			}
-			strategyResponse.Tokens[strategyToken.Symbol.String] = &StrategyToken{
+			strategyResponse.Tokens[strategyToken.Symbol] = &StrategyToken{
 				ID:         common.BytesToAddress(strategyToken.TokenID).String(),
 				ChainID:    strategyToken.ChainID,
 				MinBalance: new(big.Int).SetBytes(strategyToken.MinBalance).String(),
diff --git a/api/tokens.go b/api/tokens.go
index 0cb8acb4..490a727a 100644
--- a/api/tokens.go
+++ b/api/tokens.go
@@ -64,10 +64,10 @@ func (capi *census3API) getTokens(msg *api.APIdata, ctx *httprouter.HTTPContext)
 		tokenResponse := GetTokensItem{
 			ID:         common.BytesToAddress(tokenData.ID).String(),
 			Type:       state.TokenType(int(tokenData.TypeID)).String(),
-			Name:       tokenData.Name.String,
-			StartBlock: tokenData.CreationBlock.Int64,
-			Tags:       tokenData.Tags.String,
-			Symbol:     tokenData.Symbol.String,
+			Name:       tokenData.Name,
+			StartBlock: tokenData.CreationBlock,
+			Tags:       tokenData.Tags,
+			Symbol:     tokenData.Symbol,
 			ChainID:    tokenData.ChainID,
 		}
 		tokens.Tokens = append(tokens.Tokens, tokenResponse)
@@ -110,27 +110,6 @@ func (capi *census3API) createToken(msg *api.APIdata, ctx *httprouter.HTTPContex
 	if err != nil {
 		return ErrCantGetToken.WithErr(err)
 	}
-	var (
-		name          = new(sql.NullString)
-		symbol        = new(sql.NullString)
-		creationBlock = new(sql.NullInt64)
-		totalSupply   = new(big.Int)
-		tags          = new(sql.NullString)
-	)
-	if err := name.Scan(info.Name); err != nil {
-		return ErrCantGetToken.WithErr(err)
-	}
-	if err := symbol.Scan(info.Symbol); err != nil {
-		return ErrCantGetToken.WithErr(err)
-	}
-	if info.TotalSupply != nil {
-		totalSupply = info.TotalSupply
-	}
-	if req.Tags != "" {
-		if err := tags.Scan(req.Tags); err != nil {
-			return ErrCantGetToken.WithErr(err)
-		}
-	}
 	// init db transaction
 	tx, err := capi.db.RW.BeginTx(internalCtx, nil)
 	if err != nil {
@@ -144,14 +123,14 @@ func (capi *census3API) createToken(msg *api.APIdata, ctx *httprouter.HTTPContex
 	qtx := capi.db.QueriesRW.WithTx(tx)
 	_, err = qtx.CreateToken(internalCtx, queries.CreateTokenParams{
 		ID:            info.Address.Bytes(),
-		Name:          *name,
-		Symbol:        *symbol,
+		Name:          info.Name,
+		Symbol:        info.Symbol,
 		Decimals:      info.Decimals,
-		TotalSupply:   totalSupply.Bytes(),
-		CreationBlock: *creationBlock,
+		TotalSupply:   info.TotalSupply.Bytes(),
+		CreationBlock: 0,
 		TypeID:        uint64(tokenType),
 		Synced:        false,
-		Tags:          *tags,
+		Tags:          req.Tags,
 		ChainID:       req.ChainID,
 	})
 	if err != nil {
@@ -163,7 +142,7 @@ func (capi *census3API) createToken(msg *api.APIdata, ctx *httprouter.HTTPContex
 	// create a default strategy to support censuses over the holders of this
 	// single token
 	res, err := qtx.CreateStategy(internalCtx, queries.CreateStategyParams{
-		Alias:     fmt.Sprintf("default %s strategy", info.Symbol),
+		Alias:     fmt.Sprintf("Default strategy for token %s", info.Symbol),
 		Predicate: lexer.ScapeTokenSymbol(info.Symbol),
 	})
 	if err != nil {
@@ -253,22 +232,20 @@ func (capi *census3API) getToken(msg *api.APIdata, ctx *httprouter.HTTPContext)
 		Type:        state.TokenType(int(tokenData.TypeID)).String(),
 		Decimals:    tokenData.Decimals,
 		Size:        uint64(holders),
-		Name:        tokenData.Name.String,
-		Symbol:      tokenData.Symbol.String,
+		Name:        tokenData.Name,
+		Symbol:      tokenData.Symbol,
 		TotalSupply: new(big.Int).SetBytes(tokenData.TotalSupply).String(),
+		StartBlock:  uint64(tokenData.CreationBlock),
 		Status: &GetTokenStatusResponse{
 			AtBlock:  atBlock,
 			Synced:   tokenData.Synced,
 			Progress: tokenProgress,
 		},
-		Tags: tokenData.Tags.String,
+		Tags: tokenData.Tags,
 		// TODO: Only for the MVP, consider to remove it
 		DefaultStrategy: defaultStrategyID,
 		ChainID:         tokenData.ChainID,
 	}
-	if tokenData.CreationBlock.Valid {
-		tokenResponse.StartBlock = uint64(tokenData.CreationBlock.Int64)
-	}
 	res, err := json.Marshal(tokenResponse)
 	if err != nil {
 		return ErrEncodeToken.WithErr(err)
diff --git a/db/migrations/0002_census3.sql b/db/migrations/0002_census3.sql
index bb6da442..335cc227 100644
--- a/db/migrations/0002_census3.sql
+++ b/db/migrations/0002_census3.sql
@@ -1,26 +1,26 @@
 -- +goose Up
 
 -- stategies table schema updates
-ALTER TABLE strategies ADD COLUMN alias TEXT;
+ALTER TABLE strategies ADD COLUMN alias TEXT NOT NULL DEFAULT '';
 
 -- tokens table schema updates
 CREATE TABLE tokens_copy (
     id BLOB NOT NULL,
-    name TEXT,
-    symbol TEXT,
-    decimals INTEGER,
-    total_supply BLOB,
-    creation_block BIGINT,
-    type_id INTEGER NOT NULL,
-    synced BOOLEAN NOT NULL,
-    tags TEXT,
-    chain_id INTEGER NOT NULL,
+    name TEXT NOT NULL DEFAULT '',
+    symbol TEXT NOT NULL DEFAULT '',
+    decimals INTEGER NOT NULL DEFAULT 0,
+    total_supply BLOB NOT NULL DEFAULT '',
+    creation_block BIGINT NOT NULL DEFAULT 0,
+    type_id INTEGER NOT NULL DEFAULT 0,
+    synced BOOLEAN NOT NULL DEFAULT 0,
+    tags TEXT NOT NULL DEFAULT '',
+    chain_id INTEGER NOT NULL DEFAULT 0,
     PRIMARY KEY (id, chain_id),
     FOREIGN KEY (type_id) REFERENCES token_types(id) ON DELETE CASCADE
 );
 INSERT INTO tokens_copy SELECT * FROM tokens;
 DROP TABLE tokens;
-DROP INDEX IF EXISTS idx_tokens_type_id;
+-- DROP INDEX IF EXISTS idx_tokens_type_id;
 ALTER TABLE tokens_copy RENAME TO tokens;
 CREATE INDEX idx_tokens_type_id ON tokens(type_id);
 
@@ -43,9 +43,9 @@ SELECT * FROM (
         SELECT token.chain_id FROM tokens AS token WHERE token.id = token_holders.token_id
     ) AS chain_id FROM token_holders
 );
-DROP INDEX IF EXISTS idx_token_holders_token_id;
-DROP INDEX IF EXISTS idx_token_holders_holder_id;
-DROP INDEX IF EXISTS idx_token_holders_block_id;
+-- DROP INDEX IF EXISTS idx_token_holders_token_id;
+-- DROP INDEX IF EXISTS idx_token_holders_holder_id;
+-- DROP INDEX IF EXISTS idx_token_holders_block_id;
 DROP TABLE token_holders;
 ALTER TABLE token_holders_copy RENAME TO token_holders;
 CREATE INDEX idx_token_holders_token_id ON token_holders(token_id);
@@ -69,8 +69,8 @@ SELECT * FROM (
     ) AS chain_id FROM strategy_tokens
 );
 
-DROP INDEX IF EXISTS idx_strategy_tokens_strategy_id;
-DROP INDEX IF EXISTS idx_strategy_tokens_token_id;
+-- DROP INDEX IF EXISTS idx_strategy_tokens_strategy_id;
+-- DROP INDEX IF EXISTS idx_strategy_tokens_token_id;
 DROP TABLE strategy_tokens;
 ALTER TABLE strategy_tokens_copy RENAME TO strategy_tokens;
 CREATE INDEX idx_strategy_tokens_strategy_id ON strategy_tokens(strategy_id);
diff --git a/db/sqlc/blocks.sql.go b/db/sqlc/blocks.sql.go
index 7d8d1c81..4276dddc 100644
--- a/db/sqlc/blocks.sql.go
+++ b/db/sqlc/blocks.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: blocks.sql
 
 package queries
diff --git a/db/sqlc/censuses.sql.go b/db/sqlc/censuses.sql.go
index 1e3da650..eb374bf3 100644
--- a/db/sqlc/censuses.sql.go
+++ b/db/sqlc/censuses.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: censuses.sql
 
 package queries
diff --git a/db/sqlc/db.go b/db/sqlc/db.go
index 99526a5a..7427aff6 100644
--- a/db/sqlc/db.go
+++ b/db/sqlc/db.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 
 package queries
 
diff --git a/db/sqlc/holders.sql.go b/db/sqlc/holders.sql.go
index 858b9744..b2fa627c 100644
--- a/db/sqlc/holders.sql.go
+++ b/db/sqlc/holders.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: holders.sql
 
 package queries
diff --git a/db/sqlc/models.go b/db/sqlc/models.go
index e8e62415..1a216661 100644
--- a/db/sqlc/models.go
+++ b/db/sqlc/models.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 
 package queries
 
@@ -33,27 +33,27 @@ type Holder struct {
 
 type Strategy struct {
 	ID        uint64
-	Alias     string
 	Predicate string
+	Alias     string
 }
 
 type StrategyToken struct {
 	StrategyID uint64
 	TokenID    []byte
-	ChainID    uint64
 	MinBalance []byte
+	ChainID    uint64
 }
 
 type Token struct {
 	ID            annotations.Address
-	Name          sql.NullString
-	Symbol        sql.NullString
+	Name          string
+	Symbol        string
 	Decimals      uint64
 	TotalSupply   annotations.BigInt
-	CreationBlock sql.NullInt64
+	CreationBlock int64
 	TypeID        uint64
 	Synced        bool
-	Tags          sql.NullString
+	Tags          string
 	ChainID       uint64
 }
 
diff --git a/db/sqlc/strategies.sql.go b/db/sqlc/strategies.sql.go
index b67b37c5..bfcab4ba 100644
--- a/db/sqlc/strategies.sql.go
+++ b/db/sqlc/strategies.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: strategies.sql
 
 package queries
@@ -53,7 +53,7 @@ func (q *Queries) CreateStrategyToken(ctx context.Context, arg CreateStrategyTok
 }
 
 const listStrategies = `-- name: ListStrategies :many
-SELECT id, alias, predicate FROM strategies
+SELECT id, predicate, alias FROM strategies
 ORDER BY id
 `
 
@@ -66,7 +66,7 @@ func (q *Queries) ListStrategies(ctx context.Context) ([]Strategy, error) {
 	var items []Strategy
 	for rows.Next() {
 		var i Strategy
-		if err := rows.Scan(&i.ID, &i.Alias, &i.Predicate); err != nil {
+		if err := rows.Scan(&i.ID, &i.Predicate, &i.Alias); err != nil {
 			return nil, err
 		}
 		items = append(items, i)
@@ -81,7 +81,7 @@ func (q *Queries) ListStrategies(ctx context.Context) ([]Strategy, error) {
 }
 
 const strategiesByTokenID = `-- name: StrategiesByTokenID :many
-SELECT s.id, s.alias, s.predicate FROM strategies s
+SELECT s.id, s.predicate, s.alias FROM strategies s
 JOIN strategy_tokens st ON st.strategy_id = s.id
 WHERE st.token_id = ?
 ORDER BY s.id
@@ -96,7 +96,7 @@ func (q *Queries) StrategiesByTokenID(ctx context.Context, tokenID []byte) ([]St
 	var items []Strategy
 	for rows.Next() {
 		var i Strategy
-		if err := rows.Scan(&i.ID, &i.Alias, &i.Predicate); err != nil {
+		if err := rows.Scan(&i.ID, &i.Predicate, &i.Alias); err != nil {
 			return nil, err
 		}
 		items = append(items, i)
@@ -111,7 +111,7 @@ func (q *Queries) StrategiesByTokenID(ctx context.Context, tokenID []byte) ([]St
 }
 
 const strategyByID = `-- name: StrategyByID :one
-SELECT id, alias, predicate FROM strategies
+SELECT id, predicate, alias FROM strategies
 WHERE id = ?
 LIMIT 1
 `
@@ -119,12 +119,12 @@ LIMIT 1
 func (q *Queries) StrategyByID(ctx context.Context, id uint64) (Strategy, error) {
 	row := q.db.QueryRowContext(ctx, strategyByID, id)
 	var i Strategy
-	err := row.Scan(&i.ID, &i.Alias, &i.Predicate)
+	err := row.Scan(&i.ID, &i.Predicate, &i.Alias)
 	return i, err
 }
 
 const strategyTokens = `-- name: StrategyTokens :many
-SELECT strategy_id, token_id, chain_id, min_balance
+SELECT strategy_id, token_id, min_balance, chain_id
 FROM strategy_tokens
 ORDER BY strategy_id, token_id
 `
@@ -141,8 +141,8 @@ func (q *Queries) StrategyTokens(ctx context.Context) ([]StrategyToken, error) {
 		if err := rows.Scan(
 			&i.StrategyID,
 			&i.TokenID,
-			&i.ChainID,
 			&i.MinBalance,
+			&i.ChainID,
 		); err != nil {
 			return nil, err
 		}
@@ -158,7 +158,7 @@ func (q *Queries) StrategyTokens(ctx context.Context) ([]StrategyToken, error) {
 }
 
 const strategyTokensByStrategyID = `-- name: StrategyTokensByStrategyID :many
-SELECT st.strategy_id, st.token_id, st.chain_id, st.min_balance, t.symbol
+SELECT st.strategy_id, st.token_id, st.min_balance, st.chain_id, t.symbol
 FROM strategy_tokens st
 JOIN tokens t ON t.ID = st.token_id
 WHERE strategy_id = ?
@@ -168,9 +168,9 @@ ORDER BY strategy_id, token_id
 type StrategyTokensByStrategyIDRow struct {
 	StrategyID uint64
 	TokenID    []byte
-	ChainID    uint64
 	MinBalance []byte
-	Symbol     sql.NullString
+	ChainID    uint64
+	Symbol     string
 }
 
 func (q *Queries) StrategyTokensByStrategyID(ctx context.Context, strategyID uint64) ([]StrategyTokensByStrategyIDRow, error) {
@@ -185,8 +185,8 @@ func (q *Queries) StrategyTokensByStrategyID(ctx context.Context, strategyID uin
 		if err := rows.Scan(
 			&i.StrategyID,
 			&i.TokenID,
-			&i.ChainID,
 			&i.MinBalance,
+			&i.ChainID,
 			&i.Symbol,
 		); err != nil {
 			return nil, err
diff --git a/db/sqlc/tokenTypes.sql.go b/db/sqlc/tokenTypes.sql.go
index 7e4df009..623b106c 100644
--- a/db/sqlc/tokenTypes.sql.go
+++ b/db/sqlc/tokenTypes.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: tokenTypes.sql
 
 package queries
diff --git a/db/sqlc/tokens.sql.go b/db/sqlc/tokens.sql.go
index be38e73d..6233907c 100644
--- a/db/sqlc/tokens.sql.go
+++ b/db/sqlc/tokens.sql.go
@@ -1,6 +1,6 @@
 // Code generated by sqlc. DO NOT EDIT.
 // versions:
-//   sqlc v1.20.0
+//   sqlc v1.22.0
 // source: tokens.sql
 
 package queries
@@ -32,14 +32,14 @@ VALUES (
 
 type CreateTokenParams struct {
 	ID            annotations.Address
-	Name          sql.NullString
-	Symbol        sql.NullString
+	Name          string
+	Symbol        string
 	Decimals      uint64
 	TotalSupply   annotations.BigInt
-	CreationBlock sql.NullInt64
+	CreationBlock int64
 	TypeID        uint64
 	Synced        bool
-	Tags          sql.NullString
+	Tags          string
 	ChainID       uint64
 }
 
@@ -155,7 +155,7 @@ func (q *Queries) TokenByID(ctx context.Context, id annotations.Address) (Token,
 }
 
 const tokensByStrategyID = `-- name: TokensByStrategyID :many
-SELECT t.id, t.name, t.symbol, t.decimals, t.total_supply, t.creation_block, t.type_id, t.synced, t.tags, t.chain_id, st.strategy_id, st.token_id, st.chain_id, st.min_balance FROM tokens t
+SELECT t.id, t.name, t.symbol, t.decimals, t.total_supply, t.creation_block, t.type_id, t.synced, t.tags, t.chain_id, st.strategy_id, st.token_id, st.min_balance, st.chain_id FROM tokens t
 JOIN strategy_tokens st ON st.token_id = t.id
 WHERE st.strategy_id = ?
 ORDER BY t.name
@@ -163,19 +163,19 @@ ORDER BY t.name
 
 type TokensByStrategyIDRow struct {
 	ID            annotations.Address
-	Name          sql.NullString
-	Symbol        sql.NullString
+	Name          string
+	Symbol        string
 	Decimals      uint64
 	TotalSupply   annotations.BigInt
-	CreationBlock sql.NullInt64
+	CreationBlock int64
 	TypeID        uint64
 	Synced        bool
-	Tags          sql.NullString
+	Tags          string
 	ChainID       uint64
 	StrategyID    uint64
 	TokenID       []byte
-	ChainID_2     uint64
 	MinBalance    []byte
+	ChainID_2     uint64
 }
 
 func (q *Queries) TokensByStrategyID(ctx context.Context, strategyID uint64) ([]TokensByStrategyIDRow, error) {
@@ -200,8 +200,8 @@ func (q *Queries) TokensByStrategyID(ctx context.Context, strategyID uint64) ([]
 			&i.ChainID,
 			&i.StrategyID,
 			&i.TokenID,
-			&i.ChainID_2,
 			&i.MinBalance,
+			&i.ChainID_2,
 		); err != nil {
 			return nil, err
 		}
@@ -223,7 +223,7 @@ WHERE id = ?
 `
 
 type UpdateTokenCreationBlockParams struct {
-	CreationBlock sql.NullInt64
+	CreationBlock int64
 	ID            annotations.Address
 }
 
diff --git a/service/helper_test.go b/service/helper_test.go
index bc01c299..5002d134 100644
--- a/service/helper_test.go
+++ b/service/helper_test.go
@@ -1,7 +1,6 @@
 package service
 
 import (
-	"database/sql"
 	"math/big"
 	"os"
 	"testing"
@@ -70,11 +69,11 @@ func testTokenParams(id, name, symbol string, creationBlock, decimals, typeID ui
 ) queries.CreateTokenParams {
 	return queries.CreateTokenParams{
 		ID:            common.HexToAddress(id).Bytes(),
-		Name:          sql.NullString{String: name, Valid: name != ""},
-		Symbol:        sql.NullString{String: symbol, Valid: symbol != ""},
+		Name:          name,
+		Symbol:        symbol,
 		Decimals:      decimals,
 		TotalSupply:   new(big.Int).SetInt64(int64(totalSupply)).Bytes(),
-		CreationBlock: sql.NullInt64{Int64: int64(creationBlock), Valid: creationBlock != 0},
+		CreationBlock: int64(creationBlock),
 		TypeID:        typeID,
 		Synced:        synced,
 		ChainID:       chainID,
diff --git a/service/holder_scanner_test.go b/service/holder_scanner_test.go
index e80dd90f..aa19dc51 100644
--- a/service/holder_scanner_test.go
+++ b/service/holder_scanner_test.go
@@ -224,5 +224,5 @@ func Test_calcTokenCreationBlock(t *testing.T) {
 	c.Assert(hs.calcTokenCreationBlock(context.Background(), MonkeysAddress), qt.IsNil)
 	token, err := testdb.db.QueriesRW.TokenByID(context.Background(), MonkeysAddress.Bytes())
 	c.Assert(err, qt.IsNil)
-	c.Assert(uint64(token.CreationBlock.Int64), qt.Equals, MonkeysCreationBlock)
+	c.Assert(uint64(token.CreationBlock), qt.Equals, MonkeysCreationBlock)
 }
diff --git a/service/holders_scanner.go b/service/holders_scanner.go
index 3094f17e..8c47c8cf 100644
--- a/service/holders_scanner.go
+++ b/service/holders_scanner.go
@@ -131,7 +131,7 @@ func (s *HoldersScanner) tokenAddresses() (map[common.Address]bool, error) {
 	// parse and return token addresses
 	results := make(map[common.Address]bool)
 	for _, token := range tokens {
-		results[common.BytesToAddress(token.ID)] = token.CreationBlock.Valid
+		results[common.BytesToAddress(token.ID)] = token.CreationBlock != 0
 	}
 	return results, nil
 }
@@ -315,7 +315,7 @@ func (s *HoldersScanner) scanHolders(ctx context.Context, addr common.Address) (
 			return false, err
 		}
 		ttype := state.TokenType(tokenInfo.TypeID)
-		tokenLastBlock := uint64(tokenInfo.CreationBlock.Int64)
+		tokenLastBlock := uint64(tokenInfo.CreationBlock)
 		if blockNumber, err := s.db.QueriesRO.LastBlockByTokenID(ctx, addr.Bytes()); err == nil {
 			tokenLastBlock = blockNumber
 		}
@@ -395,15 +395,11 @@ func (s *HoldersScanner) calcTokenCreationBlock(ctx context.Context, addr common
 	if err != nil {
 		return fmt.Errorf("error getting token creation block: %w", err)
 	}
-	dbCreationBlock := new(sql.NullInt64)
-	if err := dbCreationBlock.Scan(creationBlock); err != nil {
-		return fmt.Errorf("error getting token creation block value: %w", err)
-	}
 	// save the creation block into the database
 	_, err = s.db.QueriesRW.UpdateTokenCreationBlock(ctx,
 		queries.UpdateTokenCreationBlockParams{
 			ID:            addr.Bytes(),
-			CreationBlock: *dbCreationBlock,
+			CreationBlock: int64(creationBlock),
 		})
 	if err != nil {
 		return fmt.Errorf("error updating token creation block on the database: %w", err)